Building a Graber i3

So i pulled the trigger on a Graber i3 frame. Looking at shipping time it probably wont reach me in the US at least for a month which is fine since im probably going to spend 3 months just on parts sourcing

I have a few questions though. I was looking at the pic of z carriage's and noticed 2 Lm8uu bearings per side, I was wondering wouldn't just 1 Lm8Luu suffice instead?

Also any tips on how I can get a nice Painted finish on the frame? I would love to see some examples from some of you guys here.

I am also looking for a suggestion on where to get good quality Pre cut rods in the sizes listed below. I am even fine with a ebay / amazon seller just as long as the quality is good and not something the bearings are going to mar up and wear grooves in.

(I built a prusa i2) but its been so long ago can't remember who I got the rods from on that one lol.


2- 8mm x 317mm
2- 8mm x 342mm
2- 8mm x 400mm

You want hardened rails for LM8UU bearings or the balls will chew up the rails quickly. If they don't say they are hardened, they aren't. You can cut hardened rails to length using a cutoff wheel on a grinder or a chop saw.

There's always a little slop in LM8UU bearings, so if they used 4, you'd probably better use 4. Alternatively, you can get extra long bearings, but those may not fit the rest of the parts.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Quote
the_digital_dentist
You want hardened rails for LM8UU bearings or the balls will chew up the rails quickly. If they don't say they are hardened, they aren't. You can cut hardened rails to length using a cutoff wheel on a grinder or a chop saw.

There's always a little slop in LM8UU bearings, so if they used 4, you'd probably better use 4. Alternatively, you can get extra long bearings, but those may not fit the rest of the parts.

Thanks for the tip, as far as the bearings go looking at the pics of and how they go together I don't see where it would be a issue. I will order both and probably just try it out to see if it works or not.

I have been looking around for the rods periodically today and ive found a few places. I am waiting for a response from a ebay seller. They clearly specify "hardened" rods but I am waiting on a confirmation on what type of steel they are using.

I bought these 10mm rods. 500mm cut to length and they even sent the pieces that were cut off. No wear on mine. Very happy.. You'll have to contact seller for a link to the 8mm rods.


[www.aliexpress.com]

He responded to me and said the Steel he uses is st20 ? I tried looking up data on that and it just keeps taking me to linear bearings info or steel pipe but I don't see any hardness info on st20